About

About CoverCalc

One job, done well. CoverCalc exists because "how much paint do I need?" deserves a fast, honest answer without a sign-up wall.

Why we built it

Most paint calculators are buried inside retailer sites, ask for your email, or hide the math. CoverCalc shows every number — total wall area, deductions for doors and windows, coats, and coverage — so you can check the estimate yourself. It works on a phone, standing in the paint aisle.

How the math works

Wall area is the room perimeter times the ceiling height. We subtract roughly 21 sq ft per door and 15 sq ft per window, multiply by the number of coats, and divide by the coverage rate on the can (350 sq ft per gallon is a typical interior default). Then we round up to whole gallons. The how it works section and our coverage guide go deeper.

How we make money

The calculator is free. CoverCalc currently earns a small commission from qualifying Amazon purchases made through its tagged links. Quote and sample links are ordinary destination links until a partner supplies verified tracking. That never changes the estimate. Full details are in our affiliate disclosure.

Sources and corrections

Product coverage figures come from the manufacturers' technical data sheets and are linked on the coverage-by-brand reference page. Our assumptions and formulas are published on how we calculate. We correct a published number when its source changes or a reader identifies a credible issue; please send the page and source if you spot one.

Who's behind it

CoverCalc is an independent site built and maintained by a small design studio in Los Angeles. It isn't affiliated with any paint manufacturer or home-improvement retailer. Spotted a mistake or have a suggestion? Get in touch.